US2256764A - Foodstuff packaging process - Google Patents

Description

Patented Sept. 23, 1941 2,256,764 FOODSTUFF PACKAGING PROCESS Henery M. Scott, Sweetwater, Tenn.

Application September 26, 1939,

No Drawing.

. Serial No. 296,708

3 Claims.

This invention relates to improvements in methods of packaging foodstuffs and especially is concerned with a novel process for sealing foodstuffs enveloped in sheet cellulose.

It presently is the practice when packaging 5 foodstuffs enveloped in sheet cellulose to seal the package by immersing th same in molten sealing composition. However, this procedureis unsatisfactory for several reasons among which may be included that the immersion of the packaged foodstuff in molten composition is wasteful of the composition and frequently causes rupture of the envelope because of heating and consequent expansion of gas therein. In any event the heating of th foodstuff by immersion in the 1 composition is wasteful of thermoenergy, duplicates heating of the foodstuff and in many instances impairs the quality, that is the taste or appearance of the product.

An industrial want has been felt for a process of packaging foodstuffs wherein means would be provided for rendering the packaging material intrinsically adherent to itself, thereby permitting ciosing and sealing of the package merely by folding free edge portions thereof against each other. A want has also been felt for a translucent packaging material which would be readily adherent to certain foodstuffs commonly sold in unit packages such as cheese, sandwich preparations and the like.

It is an object of the present invention to provide a process answering these industrial wants ,wherein for the first time is provided a process for packaging foodstuffs permitting the sealing of a fodstufl within an envelope merely by the foldmg of edge portions thereof against each other.

Another object of this invention is to provide a novel sheet cellulose material from which packages or package liners can be made which is superficially coated with thermosensitive composltion, soft and adherent at elevated temperatures both to the sheet cellulose and to foodstuffs An important and noteworthy feature of the novel packaging process according to this invention is that it provides at the inner face between foodstuff and envelope an essentially tasteless, easily fusible film of composition adherent both to the envelope and to the foodstuff whereby, when the contents of the package have been exposed and partially used, the package may again be closed by pressing parts of the envelope against exposed surfaces of the foodstuff.

An advantage of the novel process according to the present invention over other packaging processes now commonly in use is that in its 5 cellulose as used practice the heat content of fused foodstuff is utilized to facilitate sealing of the package.

Other objects, advantages and features of the new and improved process according to the present invention will be apparent to those skilled in this art during the course of the following description.

Regarded in certain of its broader aspects the novel packaging process according to the present invention comprises the steps of forming an open blank from sheet cellulose internally coated with a composition soft and adherent at temperatures below the boiling point of water, introducing into said blank quantities of fused foodstuff at a temperature such that at that temperature the blank coating is soft and adherent,

and thereafter folding-free edge portions of the' tion a specific embodiment thereof now preferred will be hereinafter described, but it is clearly to be understood that this specific embodiment is provided by way of illustration of the practice of this invention and not by way of limitation thereof except insofar as the scope of this invention is defined by the subjoined claims read in the light of this specification and of the prior art.'

The preferred mode of treating said cellulose will first be described. By the expression sheet in this specification and in the claims is meant regenerated cellulose such as the essentially transparent films sold under the trade name of Cellophane," and the like and also treated or untreated matted translucent flbrous sheets such as certain grades of paper. The sheet cellulose, conveniently stored on rolls, is passed between polished calendering rollers, steam heated to a temperature of the order of to 150 C. (200 to 300 F.). A coating is applied to the fibrous sheet by the calendering rolls, the coating comprising an essentially apparently homogeneous substantially tasteless mixture of wax and turpentine. It is presently preferred to prepare the composition by heating beeswax to a temperature of about C. (200 F.) and to add the heated wax to about two percent of its volume of turpentine, the substance of course being thoroughly mixed to assure homogeneity of the product. The pressure of the calendering rolls is adjusted whereby the film produced on the surface of the sheet cellu-.

'5 lose is of definite but very small thickness.

In accordance with the invention as presently practiced, the coated sheet cellulose next is cut into package blanks and the blanks are folded whereby the coated surfac faces the interior of the package. The folded blanks are then supported and fused foodstuff is introduced into the interior to an intermediate level after which the free marginal portions of the package are folded against each other and against the food-- stuff causing the package to be closed and sealed. It is clearly to be understood that the coating composition softens and becomes adherent at temperatures below the boiling point of water and that the temperature of the fused foodstuff introduced into the supported blank is such as to I cause softening of th coating. It further is to be understood that the folding of the marginal portions of the package blank is to be done at a time interval subsequent to .the'introduction of the foodstuff such that the heat content of the foodstuff has not in'the interval been -sub-.

stantially dissipated, or in other words, the folding is to-be done under conditions such that the heat content of the foodstuff will cause the marginal potions of the package when folded materially to adhere, thereby sealing the contents.

The packaged material so prepared is not disagreeable in appearance inasmuch as the wrapping, if made from substantially transparent regenerated cellulose, is translucent and gray-white in color. As mentioned, when the package has been opened and a portion of the contents thereof used, the unused balance may be protected merely byfolding parts of the coated sheet cellulose a ainst the foodstuff to which the same will adhere, protecting the foodstuflf from deleterious effects ascribable to the atmosphere.

While the proportions of beeswax and turpentine referred to above in. the description of the specific embodiment of this invention are not deemed critical in the sense that small variations therein may not be made, they nevertheless are critical in the sense that substantialvariations in the indicated proportions will provide a product less satisfactory for the indicated purposes than that specified. Experienceindicates that the major portion of the composition, that is to say, at least 90% thereof based upon weight, should be formed of beeswax and that the vturpentine should be admixed therewith to the extent of about-two percent by volum of the total mass. Under these conditions the product is tough and relatively less friable than beeswax and is of a gray, translucent character. when employed as above indicated, the composition is substantially tasteless and is not noticed during consumption of the packaged product.

It will of course be apparent to those skilled in this art that variations in the above described procedure and modifications in the above described composition may be made without departure from the spirit of this invention and the scope of the subjoined claims.

Having thus described the present invention, what it is desired to secure by Letters Patent is:

1. Process of packaging fusible cheese com prising forming an open package of sheet cellulose internally coated with a composition comprising approximately 90% beeswax and.10% turpentine, charging the packag with fused cheese at a temperature such that the coating composition is softened and made'adherent and immediately folding marginal parts of the package to close th same.

2. Process of packing cheese in a package formed of folded sheet cellulose internally superflcially coated with a' beeswax-turpentine composition comprising at least ninety percent by weight wax and approximately 10% turpentine, which comprises charging the package with cheese at a temperature such that the package coating is softened and made adherent and thereafter closing the package by folding marginal portions thereof under conditions such that said portions mutually adhere,sealing the package. Y

3. Process of packing cheese comprising forming a folded supported blank of sheet cellulose internally coated with a composition comprising at least 90% by weight of beeswax and minor proportions ofturpentine, soft and adherent at temperatures below the boiling point of water; charging said blank with melted cheese heated to a temperatureof at least about (3.; and thereafter folding free edge portions of the blank against the heated cheese to close and seal the package.

HENERY M. sco'rn-